This invention relates generally to the manufacture of hoses and more particularly to the manufacture of hoses in need of enhanced flexibility along with abrasion and chemical resistance.
The hose goes back to antiquity. It is fundamental to the operation of almost all machines and forms the linchpin upon which many technological advances depend. Improvement in basic hoses have allowed advancements in: aerial refueling; breathing in outer-space; solar heating collectors; ship-to-ship refueling; chemically and biologically resistant delivery systems; and deep sea diving.
In many applications, there is a significant need for a hose which has a highly durable outer coating to resist damage, wear and chemical degradation during handling. Unfortunately, the vast majority of durable materials which can be used in this context are stiff which promotes kinking and early failure. When a hose is made of this type of material, often the hose becomes so rigid it resembles a pipe more than a hose.
While stiffness may be acceptable in small lengths and in certain applications, the need to coil the hose for storage, bend for attachment ease, or flex during usage without inflicting permanent damage, becomes more problematic.
In one common method to improve the flexibility of such a hose, current technology uses a cure wrap placed over the uncured hose and a rope is tightly wound around the cure wrap. During the curing process, the rope's natural tautness and shrinkage, causes corrugations in the outside of the hose. While this does serve to improve the flexibility of the hose, it falls short of achieving all of the benefits sought.
It is clear that there is a need for a production process which will enhance hose flexibility, improve abrasion resistance, and prevent other surface and chemical damage, while employing a wider range of desirable surface materials.